package com.study.lock;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * 定义资源类，包含属性和方法
 */
class Share {

    private int number = 0;

    // 创建lock
    private Lock lock = new ReentrantLock();
    private Condition condition = lock.newCondition();

    // +1
    public void incr() throws InterruptedException {
        lock.lock();
        try {
            while (number != 0) {
                condition.await();
            }
            number++;
            System.out.println(Thread.currentThread().getName()+" :: "+number);
            condition.signalAll();
        } finally {
            lock.unlock();
        }
    }

    // -1
    public void decr() throws InterruptedException {
        lock.lock();
        try {
            while (number != 1) {
                condition.await();
            }
            number--;
            System.out.println(Thread.currentThread().getName()+" :: "+number);
            condition.signalAll();
        } finally {
            lock.unlock();
        }
    }

}

/**
 * @author wanghao
 * @version v1.0
 * @description: 线程间通信
 * @date 2021/12/27 9:51
 * @change [修改时间] [修改者]@[版本号] [修改内容说明]
 */
public class ThreadDemo2 {

    public static void main(String[] args) {
        Share share = new Share();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    share.incr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"AA").start();

        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    share.decr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"BB").start();

        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    share.incr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"CC").start();

        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    share.decr();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"DD").start();
    }
}
